Monday, February 05, 2018

How Many Runs Will The Tigers Allow in 2018?

The Tigers are hoping for a strong season from left-handed starter Daniel Norris(Photo credit: MLive.com) Now that I have projected the Tigers runs scoredtotal for 2018, the next step is to estimate how many runs they will give up. While I have been quite accurate in my runs scored projections the last few years, I have not been so successful in forecasting runs allowed. Run prevention is more difficult to predict because pitcher's arms are so fragile and their performance so volatile. I undershot the Tigers eventual run total in each of the last four seasons:2014 652015 1292016 302017 194

That 194 is not a typo. Before the 2017 season got under way, I wrote that the Tigers would allow 700 runs. They went on to allow 894 runs. Yes, 894 runs! Did you forget how bad they were last year? I underestimated their total runs allowed by a whopping 22%. As is often the case with pitching, a lot of things went wrong. Jordan Zimmermann continued to struggle with a neck injury and his ERA soared to 6.08. Last year's Rookie Of The Year Michael Fulmer was eventually shut down with in an irritated nerve in his elbow and promising young pitchers Daniel Norris (5.31 ERA) and Matt Boyd both disappointed. Moreover, long-time ace Justin Verlander and top reliever Justin Wilson were traded during the season. Finally, they got little help from the minors with most of the call-ups posting ERAs north of six. General Manager Al Avila did not make many big moves during the off-season. The most notable acquisition was right hander Mike Fiers who posted a 5.22 ERA with 146 strikeouts in 153 innings with Houston last year. One hope for 2018 is that Fulmer will come back healthy and that Norris and Boyd will make some progress. The other hope is that their minor league depth will not be as disasterous as last year. For the projection, I first estimated the innings pitched in 2018 for their five expected starters and key bullpen pieces at the beginning of the season (Table 1). In order to forecast runs allowed, I used three-year averages on three measures from 2015-2017 all adjusted for projected innings this year:

Runs Allowed.

Base Runs - estimate of what runs allowed should have been based on base runners, total bases and home runs.

For example, Zimmermann allowed an average of 91 runs per 165 innings (his projected 2018 total) from 2015-2017. He also allowed 89 Base Runs and 80 FIP Runs. The average of the three numbers above (91, 89, 80) was 87. I think Zimmermann's 2015 season with Washington pulled his three-year average to a level beyond his true current talent. So, I am bumping up his projected run total to 95 runs in 2018.

I projected the rest of the pitchers similarly moving them up or down from their three-year averages if I think they are going to get better or worse this year. In particular, I'm guessing that reliever Shane Greene will do better than his three-year average. Norris and Boyd may do a little better, but I don't want to give them a big boost unless they look especially good in spring training. Other than Zimmermann, I don't expect anyone to be much worse than their three-year averages. Summing it all up, I am projecting 790 runs allowed which is approximately half-way between last year's projection and last year's reality. That combined 685 runs scored yields a differential of 105 runs or eleven wins below .500. Thus, my early call for the season is a 70-92 record which doesn't sound so bad versus 98 losses in 2017. I will take a look at this again before the season making adjustments for any injuries or other surprises that may occur.Table 1: Projected Runs Allowed By Tigers Pitchers in 2018